This Recommendation defines the object-oriented data features of the Specification and Description Language building on the foundation of the data definitions and expressions defined in Rec. ITU-T Z.104. Together with Recs. ITU-T Z.100, Z.101, Z.102, Z.103, Z.104, Z.105 and Z.106 this Recommendation is part of a reference manual for the language. The language defined in this document partially overlaps features of the language included in basic SDL 2010 in Rec. ITU-T Z.101 and used in comprehensive SDL 2010 in Rec. ITU-T Z.102 and the features of Recs. ITU-T Z.103 and Z.104.